Computer Basics
• Define a computer
• Understand the use of computers in everyday life
• Identify the benefits and limitations of computers
• Understand the different generations of computers
• Identify the types of computer systems
• Identify the basic components of the computer
• Understand the working of a computer
• Know about input and output devices
• Understand the storage capacity of a computer
• Explain about the various storage media and disk drives
• Define software
• List the types of software
• List the different types of computer languages
• What is a Computer?
A computer can be defined as an electronic device that can accept store
and process data to produce the required result according to user direction .
Uses of a Computer
Computers are used in:
• Airline and Railway Reservations
• Medical Diagnosis
• Weather Forecasting
• Payment of telephone and electricity bills
• Banking
• Manufacturing products like automobiles, shoes, computer cabinets, etc.
• Cartoon Film Production
• Space Research
• Creation of blueprints for houses
• Benefits and Limitations of a Computer
• The various benefits of computers are:
• Speed –
Computers are very fast.
• Accuracy –
Computers are very accurate. If the input is right, they never make mistakes.
• Diligence –
Computers never get tired or bored of doing the same task continuously. They work in the same manner all the time.
• Storage –
A computer can store large amounts of information in its memory.
• Automation –
If a task has to be performed several times, the computer needs to be instructed only once and it automatically completes the task.
• The limitations of a computer are:
• It cannot perform any task on its own. We need to give the computer instructions on exactly what it has to do.
• If an unanticipated situation arises, computers will either produce wrong results or abandon the task all together. They do not have the potential to work out alternate solutions.
• Generations of Computers
The growth of a computer can be classified into five generations of Computers.
• First Generation
– The basic component of the first generation of computers was vacuum tubes. A vacuum tube is an electronic device that permitted the processing of digital signals at a faster speed.
• Second Generation
– The second generation of computers used a solid-state device called transistor in the place of vacuum tubes. Transistors were very convenient when compared to vacuum tubes. They were more efficient and cheaper than the vacuum tubes.
• Third Generation
– Though transistors were an improvement over the vacuum tube, they still had some limitations. They had complex circuits with numerous connections between the individual transistors.
– A major breakthrough was achieved when hundreds of transistors were successfully connected together and placed on a single silicon chip called the Integrated Circuit (IC). The use of IC chips in the place of transistors gave birth to third generation of computers.
• Fourth Generation
– LSI technology led to the development of Very Large Scale Integration (VLSI) where millions of transistors could be placed on a single chip called the Microprocessor. This was the basic component of fourth generation of computers. The VLSI chips could perform faster calculations
• Fifth Generation
– In this generation, researches are focused on developing “thinking computers”. This technology is referred to as Artificial Intelligence. These computers are called the fifth generation computers. The computers you are using now belong to the fifth generation of computers.
Types of Computers
• Based on the size, cost and performance, computers can classified into:
– Micro computers
– Mini computers
– Mainframes
– Super computers
• Micro Computers
• Microcomputers are also called as personal computers (PCs). These computers use microprocessors.
• They are small in size and they can perform difficult tasks.
• They are used mainly for desktop publishing, accounting, statistical analysis, graphics designing and project management.
• The classification of PCs is as follows:
– Desktops
– Portables
• Laptops
• Notebooks
• Palmtops
Mini Computers
• Minicomputers are small general-purpose computers. These computers can perform more complex tasks and cost more than microcomputers.
• They are larger in size and they have small to medium storage capacity.
• They are used for processing data and analysing results of experiments. They are also used for controlling and monitoring production processes.
• Some examples are PDP 11/42 and VAX 11.
Mainframe Computers
• Mainframes are more powerful than minicomputers.
• They have high processing speeds and can store large amounts of data. They are used in wide area networks and support hundreds of users. However, these computers consume more electricity.
• Some examples are IBM 3000 series and Univac 1180.
Super Computers
• Supercomputers are the largest and fastest computers. They are also the costliest computers.
• They are used in fields like science and defence. These computers are used for designing and launching missiles, weather forecasting, biomedical research, aircraft design and automobile design.
• There are only a few supercomputers throughout the world. India owns a series of supercomputers called PARAM developed by C-DAC.
